Non-interchangeability means for circuit breakers



Jan. 11, 1966 w. H. EDMUNDS 3 Sheets-Sheet l Jan. l1, 1966 w. H. EDMUNDs 3,229,156

NoN-INTERCHANGEABILITY MEANS FOR CIRCUIT BREAKERS Filed June 10, 1960 5 Sheets-Sheet 2 Jan. 11, 1966 w. H. EDMUNDS 3,229,166

NON-INTERCHANGEABILITY MEANS FOR CIRCUIT BREAKERS Filed June 10. 1960 5 Sheets-Sheet 5 United States Patent O l 3,229,166 NON-INTERCHANGEARILITY MEANS EUR` y CIRCUIT BREAKERS William Harold Edmunds, Havertown, Pa., assigner to I-T-E Circuit Breaker Company, Philadelphia, Pa., a

corporation of Pennsylvania Filed June 10, 7.960, Ser. No. 35,369

Claims. (Cl. 317-119) The instant invention generally relates to circuit breakers having non-interchangeability means and more particularly to circuit breakers 'of this type wherein tampering with the non-interchangeability means is discoraged since destruction of the material portion of the circuit breaker housing will result.

My copending application Serial No. 626,442, filed December 5, 1956, 'entitled Selective Mounting for Circuit Interrupters n'ow US. Patent No. 3,120,628 issued February 4, 1964, and assigned to the assignee of the instant invention se'ts forth a construction whereby a circuit breaker of high current rating cannot be inserted at a panelboard location adapted to receive only circuit breakers of a lower current rating. rl`his is accomplished by suitably forming the'p'anelbo'ard mounting hooks and portions of the circuit breaker housing at the load end thereof 'in the region delining a recess to receive the mounting hook.

The particular circuit breakers involved are provided with housings constructed of molded 'insulated material. It has been found that the housings have often been broken away in the region of the mounting recess and in this manner a circuit breaker of high current rating has been mounted at a panelbard location adapted to exclude a circuit breaker of this rating so that a dangerous condition is created.

In order to overcome this problem, the instant invention provides means whereby an attempt to defeat the circuit breaker non-interchangeability means cannot be accomplished without destroying a considerable portion vof the circuit breaker housing and after this portion is broken away mounting of the circuit breaker within the panelboard becomes vanawkward if not impossible operation. In both embodiments of the instant invention to be hereinafter described, a hardened 'steel member is inserted in suitable recesses of the circuit breaker housing and `positioned in a manner such that if an attempt is .made to enlarge the hook receiving recess of the circuit ybreaker arconsiderable portion ofthe circuit breaker housing will be broken away and thereby expose the inside ofthe breaker.

@ne embodiment of this invention includes a hardened steel member which is L-shaped and is Aprovided with an aperture through which extends a rivet for maintaining the housing, section securedto one another.

Accordingly, a primaryV object of the instant invention is toprovide a `circuit breaker construction which discourages tampering with the circuit breaker non-interchangeability means.

Another object is to provide a member of hardened material disposed in suitable recesses of a circuit breaker molded insulating housingandoperativelypositioned in the region of the mounting recess whereby the shape of the mounting'recess cannot readily be altered without destroying a considerable portion of the circuit breaker housing and thereby exposing'the circuit breaker mechamsm.

Thesey as well as other objects of the instant invention shall become readily apparent after studying the following description of the accompanying drawings in which:-

FIGURE 1 is a perspective View of a panelboard con- Y3,229,166 Patented Jan. 11, 1966 f6 ice structed in accordance with the teachings of the instant invention. v

FIGURE 2 is an end View of the `panelboard of FIG- URE l illustrating the manner in which circuit breakers are mounted thereto.

FIGURES 3A-3C are fragmentary views of circuit breakers adapted to be mounted to the panelboard of FIGURE 1, with the fragmentary views illustrating the circuit breaker housing in the region of the load end recess for receiving the panelboard mounting hook. The circuit breaker of FIGURE 3A is of high current rating, that of FIGURE 3B is of an intermediate current rating, and that of FIGURE 3C is of a low current rating.

FIGURES lA-4C are front elevations of circuit breaker mounting hooks. The mounting hook of FIGURE 4A is constructed so as to receive any 'of the circuit breakers of FIGURES BA-S'C. The mounting hook of FIGURE 4B is constructed to receive the circuit breakers of both FIGURES 3B and 3C yet exclude the circuit breaker of FIGURE 3A. The mounting hook of FIGURE 4C is constructed to receive only the circuit breaker of FIG- URE 3C while excluding the circuit breakers of both FIGURES 3A and 3B. 4

FIGURE 5 is a cross-section of the circuit breaker of FIGURE 3B taken through line 5 5 looking in the direction of the arrows, illustrating this circuit breaker incooperation with the panelbo'ard mounting-hook.

FIGURE 6 is a cross-section Vof the circuit breaker of FIGURE 3B taken through line 6 6 looking in the direction of the arrows, illustrating this circuit breaker mounted to the panel board.

FIGURE 7 is an exploded view illustrating the hardened steel member illustrated in FIGURE 3B showing the mounting thereof to the circuit breaker and its cooperation with the panelboard mounting hoook.

FIGURE 8 is a perspective View similar'to FIGURE 7 illustrating another embodiment of this invention.

FIGURE 9 is afragmentary perspective illustrating the panelboard mounting ledge of a type utilized with still another embodiment of this invention.

FIGURE 1() is a cross-section of the mounting'ledge of FIGURE 9 taken through one of the mounting -hooks and illustrating the position occupied by a circuit breaker of high current rating.

FIGURE `11 is a perspective view of the non-interchangeability means ycarried by the circuit breaker of FIGURE 10.

FIGURE 12 is an exploded view illustrating the mounting of the hardened steel non-interchangeability member and its cooperation with the panelboard non-interchangeability means of the type illustrated in FIGURE 9 for a circuit breaker of intermediate current rating.

FIGURE 12A is a fragmentary plan view, partially sectioned. of the circuit breaker of FIGURE 12.

FIGURE 13 is a `schematic illustratingthe manner in which the hardened steel members of various ratedcircuit breakers cooperatewith the non-interchangeability means of FIGURE 9.

Now referring to the gures, panelboard 10 comprises a U-shaped'frarne 11, a sheet of insulation material 12 overlying the interior back surface of frame 11, three parallel bus bars l3-15 maintained in insulating relationship vby means of insulated mounting block I6 ina manner well known to the art. Male stabs 1'7-1'9 are connected to bus bars 13s-I5 in' a manner well known to the a'rt and are maintained in operative position by insulation block 16. Mounting ledges 20 are secured to frame 11 -along opposite sides thereof. The projection 22 of insulating block 16 extends through an aperture 23 in mounting ledge 20 to maintain insulating block I6 against movement in a longitudinal direction.

Mounting ledge 20 is provided with hooks 24-26 which cooperate with male stabs 17-19, respectively, to define circuit locations. The other mounting ledge 21"is provided with hooks 23-30 of a construction identical to hooks 24-26, respectively, and perform identical functions.

For reasons to be hereinafter explained, mounting hook 24 is provided with downwardly turned portions 32 at the free end thereof which extends across substantially the full width of lhook 24 4so as to exclude circuit breakers of high current rating, say in the range of from 50 to 100 amperes (circuit breaker 50 of FIGURE 3A) as well as circuit breakers of intermediate current ratings, say in the range of 20 to 50 amperes (circuit breaker 60 of FIG- URE 3B). Mounting hook 25 is provided with downwardly turned extension 33 at the free end thereof, which serves as a panelboard means to reject circuit breakers of a rating exceeding that intended for the particular panelboard location. It is to be noted that extension 33 is only approximately half of the width of hook 25 so as to exclude only circuit breakers 50 of high current rating from being mounted at the panelboard location defined by hook 25 and stab 18. Hook 26 is not provided with any downwardly turned extension so that the circuit breaker location defined by hook 26 and stab 19 will permit mounting of circuit breakers having a low current rating, say in the range below 20 amperes (circuit breaker 40 of FIG- URE 3C) as well as intermediate current rated circuit breaker 60 and high current rated circuit breaker 50.

Circuit breaker 60 is mounted to panelboard 10 by inserting mounting hook 25 into recess 61 at the load end of the circuit breaker housing which is comprised of a base 49 and a cover 48. After recess 61 receives hook 25 circuit breaker 60 is then pivoted about hook 25 until panelboard stab 1S ris engaged by female line connector 47 mountedwithin the circuit breaker housing 48, 49.

The non-interchangeability means for circuit breaker 60 comprises an L-shaped member 65 whose arm 66 is disposed within a suitable shaped recess 67 of cover 48 internally of housing 4S, 49. Arm 66 is provided with aperture 68 which is aligned with cover aperture 69. Rivet 70, which secures cover 48 to base 49, extends through Iapertures 68, 69 for a reason to be hereinafter explained. The leg 72 of member 65 is provided with an outward projection 73 which extends along leg 72 from the free end thereof for approximately half of the length thereof.

Circuit breaker 60 also includes a venting passage for thegaseous products of arcing with this passage partially being defined by cover grooves 74, 75 with the exhaust" passage exit from housing 48, 49 being disposed above hook receiving recess 61. Thus, arm 66 of member 65 extends above and below vent passage 74, 75.

As is clearly illustrated, especially in FIGURES and 7, projection 73 and hook extension 33 complement one another so that extension 33 and member 65 do not interfere with one another and circuit breaker 60 may be mounted at the panelboard location defined by hook 25 and stab 18. If an attempt is made to mount circuit ybreaker 60 at the panelboard location defined by hook 24 and stab 17 projection 73 will interfere with hook extension 32 and mounting of circuit breaker 60 at this location will be prevented. However, in view of the fact that hook 26 does not have a downward extension the panelboard location dened by hook 26 and stab 19 will accept circuit breaker 60.

The circuit breaker 40 of low current rating is not provided with a member in the nature of member 65 so that .opened any of thevhooks 24-26 willr readily be received by this recess so that circuit breaker 40 `may be'mounted at any of the panelboard circuit locations.

Circuit breaker of high current rating is provided with a non-interchangeability member 80 which is of substantially the same construction as non-interchangeability member 65. However, the leg 81 is provided with a forward projection 82 which substantially completely closes the bottom of mounting hook receiving recess 61. Because of this only a mounting hook, such as 26, which does not have a downward extension can be received within the recess 61 of circuit breaker 50. Thus, circuit breaker 50 may only be mounted at the locations defined by hook 26 and stab 19 or hook 30 and stab 19.

Considering the circuit breaker ofl intermediate current rating, it is noted that the non-interchangeability member is constructed of hardened steel whereas the housing portions 48, 49 `are constructed of a molded rigid insulating material which is considerably more brittle than the member 65. If an attempt is made to break away projection 73 so that circuit breaker 60 may be mounted at the panelboard location defined by hook 24 a substantial portion of housing 4S, 49 will be broken away and expose a portion of the circuit breaker mechanism.

Thereafter, it is highly doubtful as to whether the circuit breaker 60 will again be used. A similar occurrence will take place if an attempt is made to break away a portion or projection 82 of circuit breaker 50 in an attempt to modify circuit breaker 50 for mounting at one or both of the locations defined by hooks 24 and 25.

The non-interchangeability member 88 illustrated in FIGURE 8 comprises a U-shaped hardened steel member placed on its side with end 89 of the lower and longer U-arm disposed within recess 90 of housing coverv 48. The outer edge of the web 92 is disposed within a suitable recess of the circuit breaker base (not shown). Member 88 is provided with an outward projection 93 whose length is as illustrated for the case of a high current rated circuit breaker and Whose length is that of projection 33 for the case of an intermediate current rated circuit breaker. It is noted that web 92 extends across the venting passage defined by cover recess 95 as explained in connection with the embodiment of FIGURES l-7. In the embodiment of FIGURE 8, if an attempt is made to break away projection 93 in whole or part a considerable portion of the circuit breaker housing will be broken away and the circuit breaker mechanism will be exposed.

Now referring to FIGURES 9-13 wherein still another embodiment of this invention is illustrated. The panelboard non-interchangeability means is provided at each panelboard circuit breaker location by a pair of ears 101,` 102 struck from strip 103 and extending at substantially right angles therefrom. Strip 103 lies along the bottom surface of ledge 104 being secured thereto by welds or rivets. Ears 101, 102 extend upwardly through aperture 103' in mounting ledge 104 which is formed as material is struck from mounting ledge 104 to form hook 105.

As best seen in FIGURE 13, if a circuit breaker location is to reject all but circuit breakers of low current rating 107, both ears 101 and 102 must be in place. If the panelboard location is to reject only circuit breakers of high current rating 108, only ear 101 is present with ear 102 having been broken away. If the panelboard location is to accept circuit breakers of high current 109 as well as those of lower current ratings, both ears 101 and 102 must be broken away. v

The hardened steel member 110 for the circuit breaker f of high current rating 109 is illustrated in FIGURE 11.

Member 110 comprises a horizontal portion 111 and a vertical portion 112 projecting downward from portion 111 and extending for a substantial distance along-a long edge thereof. This distance is great enough so that when mounting hook is inserted into mounting recess 114 of circuit breaker 109 with portion 111 below hook 10S portion 112 would engage either or both ears 101, 102

:nojtedjthat the ,portion 122 is only half the width of portionu11121 and is positioned onone side of thetransverse Acenter lineofl portion 121. ,b Thus, when the circuit breaker .of-.intermediate A,current rating l108 ,is mounted to the panelboard, portion 122 is positioned so as to engage ear 102, should this ear .not have been removed from the location at which the circuit breaker 108 is being mounted. Should ear 102 have been removed, there will be no such engagement. Portion 122 is of such dimensions that with ear 102 removed, circuit breaker 108 may be installed on the panelboard without engaging ear 101, as shown in FIGURE 13.

Member 120 is mounted by inserting the left end 123 thereof into recess 124 in the cover 125 of circuit breaker 108. The base 126 of circuit breaker 108 is provided with recess 128 which receives the other end 127 of member 120;

As in the embodiments previously described the circuit breaker of low current rating 107 is not provided with any insert so that this circuit breaker may be mounted at any location whether or not ears 101, 102 are present in any combination.

Thus, this invention provides novel means for discouraging the tampering with the non-interchangeability means of a circuit breaker. While the invention hereinbefore described has referred to circuit breakers of high, intermediate and low current ratings with specific ranges to be given, it is to be understood that the designations high, intermediate and low are merely relative terms and are not to be limited to the specific current ranges designated.

Although I have here described preferred embodiment of my novel invention, many variations and modifications will now be apparent to those skilled in the art, and I therefore prefer to be limited, not by the specific disclosure herein, but only by the appending claims.

I claim:

1. A circuit breaker including a housing and a first means adapted to cooperate with panelboard means whereby said circuit breaker housing cannot be mounted at a panelboard location for a load of lower current rating than said circuit breaker current rating; a mounting recess in said housing, said mounting recess having a first end terminating at the external surface of said circuit breaker housing, and a second end at an internal recess extending within said housing, beyond the received location of a mounting hook, said mounting recess adapted to receive and securably mate with a panelboard mounting hook at a predetermined panelboard location; said first means comprising a non-interchangeability member including a mounting portion rigidly secured to said housing at said internal recess, and a blocking portion extending therefrom and internally located within said mounting recess; said non-interchangeability member being constructed of a material substantially stronger than the material of said housing and secured to said housing in a manner whereby an attempt to break away said noninterchangeability member in whole or part results instead in breaking away of a substantial portion of said housing, including said hook receiving mounting recess.

2. A circuit breaker including a housing and a first means adapted to cooperate with panelboard means whereby said circuit breaker housing cannot be mounted at a panelboard location for a load of lower current rating than said circuit breaker current rating; a mounting recess in said housing, said mounting recess having a first end terminating at the external surface of said circuit breaker housing, and a second end at an internal recess extending within said housing, beyond the received Ylocation of a mounting hook, said mounting recess adapted to receive and securably mate with a panelboard mounting hook ata predetermined panelboard location; said lirst means comprising a non-interchangeability member including a mounting portion rigidly secured to said housing at said internal recess, and a blocking portion extending therefrom and internally located within said mounting recess; said non-interchangeability member being constructed of a material substantially lstronger than the `material of said housing and secured to said housing in a manner whereby an attempt to break away said noninterchangeability member in whole or part results instead in breaking away of a substantial portion of said housing, including saidhook receiving mounting recess; said housing material comprising a molded rigid insulating material and the material of said non-interchangeability member comprising a hardened metal.

3. A circuit breaker including a housing having a mounting recess in the load end thereof, said mounting recess having a first end terminating at the external surface of said circuit breaker housing, and a second end at an internal recess extending Within said housing, beyond-the received location of a mounting hook adapted to receive a panelboard mounting hook, non-interchangeability means including a non-interchangeability member securably located within said housing and operatively positioned at the load end with respect to said mounting recess to prevent said circuit breaker from being mounted at a panelboard location adapted to exclude circuit breakers of higher rating than the rating of said circuit breaker; said non-interchangeability member including a blocking portion internally located within said mounting recess and a mounting portion extending therefrom, said mounting portion rigidly secured to said housing and disposed within said internal recess; said non-interchangeability member being constructed and mounted to said housing in a manner such that an attempt to defeat said non-interchangeablility means results in the destruction of a substantial portion of said housing, including said hook receiving mounting recess; said non-interchangeability member extending across substantially the entire width of said mounting recess.

4. A circuit breaker including a housing having a mounting recess in the load end thereof, said mounting recess having a rst end terminating at the external surface of said circuit breaker housing and a second end at an internal recess extending within said housing, beyond the received location of a mounting hook adapted to receive a panel board mounting hook, non-interchangeability means including a non-interchangeability member securably located Within said housing and operatively positioned with respect to said mounting recess to prevent said circuit breaker from being mounted at a panelboard location adapted to exclude circuit breakers of higher rating than the rating of said circuit breaker; said non-inter changeability member including a blocking portion internally located within said mounting recess and a mounting portion extending therefrom, said mounting portion rigidly secured to said housing and disposed within said internal recess; said non-interchangeability member being constructed and mounted to said housing in a manner such that an attempt to defeat said non-interchangeability means results in the destruction of a substantial portion of said housing, including said hook receiving mounting recess; said housing including a venting passage whose exhaust opening is positioned at said housing load end above said mounting recess; said member having a portion extending above and below said exhaust opening.

5. The combination comprising a panelboard including means defining a plurality of circuit breaker mounting locations, said means including mounting hooks at said locations, a circuit breaker of given rating including a housing mounted at a first of said locations, panelboard means associated with the mounting hook at said rst location constructed and positioned to reject circuit breakers whose ratings exceed said given rating, said housing including an externally accessible mounting recess,

.asid mounting recess adapted to receive and securely mate with said mounting hook at said first location; said mounting recess having a rst end terminating at the external surface of said circuit breaker housing, and a second end at an internal recess extending within said housing, beyond the received location of said mounting hook; a noninterchangeability member; said non-interchangeability member being complementaryto said panelboard hook and operatively positioned with respect thereto; said noninterchangeability member including a blocking portion internally located within said mounting recess and a securing portion rigidly secured to the housing structure adjacent said internal recess; said member being constructed of a material substantially stronger than the material of said housing so that an attempt to break away said member in whole or part results instead in breaking away of a substantial portion of said housing, including said hook receiving mounting recess.

References Cited by the Examiner UNITED STATES PATENTS p p l Dorfman et al. 317-119 Norden 317-119 JOHN F. BURNS, Primary Examiner..

MAX L. LEVY, Examiner. 

1. A CIRCUIT BREAKER INCLUDING A HOUSING AND A FIRST MEANS ADAPTED TO COOPERATE WITH PANELBOARD MEANS WHEREBY SAID CIRCUIT BREAKER HOUSING CANNOT BE MOUNTED AT A PANELBOARD LOCATION FOR A LOAD OF LOWER CURRENT RATING THAN SAID CIRCUIT BREAKER CURRENT RATING; A MOUNTING RECESS IN SAID HOUSING, SAID MOUNTING RECESS HAVING A FIRST END TERMINATING AT THE EXTERNAL SURFACE OF SAID CIRCUIT BREAKER HOUSING, AND A SECOND END AT AN INTERNAL RECESS EXTENDING WITHIN SAID HOUSING, BEYOND THE RECEIVED LOCATION OF A MOUNTING HOOK, SAID MOUNTING RECESS ADAPTED TO RECEIVE AND SECURABLY MATE WITH A PANELBOARD MOUNTING HOOK AT A PREDETERMINED PANELBOARD LOCATION; SAID FIRST MEANS COMPRISING A NON-INTERCHANGEABILITY MEMBER INCLUDING A MOUNTING PORTION RIGIDLY SECURED TO SAID HOUSING AT SAID INTERNAL RECESS, AND A BLOCKING PORTION EXTENDING THEREFROM AND INTERNALLY LOCATED WITHIN SAID MOUNTING RECESS; SAID NON-INTERCHANGEABILITY MEMBER BEING CONSTRUCTED OF A MATERIAL SUBSTANTIALLY STRONGER THAN THE MATERIAL OF SAID HOUSING AND SECURED TO SAID HOUSING IN A MANNER WHEREBY AN ATTEMPT TO BREAK AWAY SAID NONINTERCHANGEABILITY MEMBER IN WHOLE OR PART RESULTS INSTEAD IN BREAKING AWAY OF A SUBSTANTIAL PORTION OF SAID HOUSING, INCLUDING SAID HOOK RECEIVING MOUNTING RECESS. 